1. Technical Field
The present invention relates to an electro-optical device substrate used in an electro-optical device, such as a liquid crystal device, an EL device or the like, an electro-optical device using the electro-optical device substrate, and an electronic apparatus using the electro-optical device.
2. Related Art
Presently, in various electronic apparatuses such as a cellular phone, a portable information terminal or the like, an electro-optical device such as a liquid crystal device, an EL device or the like is commonly used. For example, the electro-optical device is used as a display for visually displaying many pieces of information on the electronic apparatus. In this electro-optical device, a device using a liquid crystal as an electro-optical material, in other words, a liquid crystal device is known. In addition, an EL (Electro Luminescence) device using an EL as an electro-optical material is also known.
The liquid crystal device typically has a structure in which a liquid crystal layer is sandwiched between a pair of substrates having respective electrodes. Alignment of liquid crystal molecules in the liquid crystal layer is controlled per a display dot by supplying light to the liquid crystal layer and at the same time, controlling a voltage applied to the liquid crystal layer per the display dot. The light supplied to the liquid crystal layer is modulated depending on alignment states of the liquid crystal molecules, and an image such as a character, a number, a figure or the like is externally displayed according to whether or not the modulated polarized light passes through a polarizer.
In this liquid crystal device, a plurality of wirings is formed on one or both of the pair of substrates to transmit a signal to each of the electrodes. As of the present time, resolution in the number of segment electrodes × the number of common electrodes of about 180×220 is adopted. In this case, it is necessary to dispose wirings of the number corresponding to the number of electrodes on the substrate.
The liquid crystal device typically includes a display region being a region in which an image such as a character or the like is displayed, and another region, a so-called frame region that is formed around the display region and does not contribute to the display. There are many cases where the plurality of wirings is typically disposed in the frame region.
In the liquid crystal device, it is a recent general trend to minimize the frame region that does not contribute to the display. That is, it is general trend to make the frame narrow. In this case, the wiring width and the wiring gap should be small with respect to a plurality of wirings that can be put in the frame region.
In addition, recently, there is an increasing demand for high-resolution displays. To realize this, a plurality of wirings having a small line width should be formed on the substrate. For example, in the case of realizing a segment electrode×common electrode=240×320 QVGA type display, it is necessary to form a plurality of wirings having, for example, a wiring width of 3 μm, a space interval between the wirings of about 3 μm, in other words, a pitch of about 3+3=6 μm dimension.
However, since reducing the wiring width and the wiring gap depending on a narrow wiring space and an increased wiring number as described above increases the wiring resistance, crosstalk is generated, thereby scattering the display image.
The present invention is conceived to solve the aforementioned problems, and it is an object of the present invention to reduce the resistance of each of a plurality of wirings formed on a substrate.